1. Field of the Invention
The present invention relates to a crane game machine.
2. Description of the Related Art
A crane game machine is designed such that when a player translates a prize catcher portion back and forth and left and right to move it to immediately above a prize which a player wants to obtain, the catcher moves down to the prize and grasps it, moves up while grasping the prize, moves horizontally to a prize drop-in port, and then releases the prize, thereby providing the prize to the player.
Such a crane game machine is generally provided with limit switches for stopping the back and forth movement, left and right movement, and up and down movement of the catcher at the respective movement limits. For the down movement of the catcher, this machine is provided with a mechanism of detecting the slack of a wire when the catcher moves down on stacked prizes, and stopping letting out the wire for the down movement of the catcher (see, e.g., Japanese Patent No. 2613597).
However, when the mechanism for detecting such slack of the wire and stopping letting out the wire is to move the catcher down above the prize drop-in port, the mechanism cannot stop moving the catcher down before the catcher enters the prize drop-in port.
Another type of crane game machine has been developed (e.g., Jpn. Pat. Appln. KOKAI Publication No. 2001-157772), which measures the number of revolutions of a wire take-up pulley and stops moving the catcher down upon comparing the measured number of revolutions with a limit value instead of using the limit switches of the mechanism for stopping letting out the wire for the down movement of the catcher.
Stop control on the up and down movement of the catcher of such a crane game machine will be described below.
A catcher elevating motor is interlocked with a wire take-up pulley through a gear, and a wire is wound around the wire take-up pulley. The other end of the wire is connected to a catcher through an extendible pipe. A shield plate which shields a photosensor is fixed to one end of the periphery of the wire take-up pulley. With this arrangement, the number of revolutions of the wire take-up pulley is counted.
A control board incorporated in the main body of the crane game machine detects a rise signal generated when a down push button is pressed, counts the number of revolutions of the wire take-up pulley which is sent from the photosensor, and automatically performs stop control on the catcher elevating motor when the number of revolutions reach a maximum number n of turns given by expression (1) in accordance with a predetermined program.L>=2π·r·n  (1)where L is the distance from the lowest end of the grip pawl of the catcher to a prize mount plate, r is the radius of the pulley, and n is the number of revolutions of the pulley.
In stop control on the up and down movement of the catcher with the above arrangement, however, since parts such as a photosensor and shield plate are required, a complicated mechanism is required, resulting in a high failure rate.
In addition, since the mechanism of the driving portion is complicated, the weight of the portion increases. As a consequence, the response with respect to operation decreases as compared with a case without such a mechanism. In order to prevent a decrease in response, a high-performance motor needs to be selected, resulting in higher part costs.
If one shield plate and one photosensor are used to count the number of times the shield plate blocks the photosensor, the number of revolutions which can be detected is limited to an integral value. However, when the maximum number n of turns to be set is to be changed, e.g., a case wherein the level of the prize mount plate is to be changed or a case wherein a lower limit is to be set in a place where the prize mount plate does not exist, e.g., the prize drop-in port, there may occur a case which cannot be handled with integral values. When control is to be performed with a finer number of revolutions than for control based on an integral value, the numbers of photosensors and shielding plates need to be increased. However, such numbers which can be increased are structurally limited, and the fineness of the number of revolutions which can be detected is limited. In addition, as the above structure problem becomes more eminent, it becomes necessary to find some comprise in terms of design.
Furthermore, the conventional crane game machine cannot recognize information concerning prizes, and hence fine control corresponding to the types of prizes cannot be performed.